Sustainable utilization of regional water resources: experiences from the Hai Hua ecological industry pilot zone (HHEIPZ) project in China

Water resource scarcity is becoming more and more serious and greatly restricts sustainable development in many locations. In this paper, the characteristics and implementation of a regional water resource sustainable utilization project in the Hai Hua Ecological Industry Pilot Zone (HHEIPZ) are described. In the project, a three-level water cycle pattern was built to relieve local water resource scarcity. The project was designed to suit the local context and operated at the individual firm level, the inter-firm level, and the regional level. The results show that the three-level water cycle was effective and provided sufficient and continuous water supply for sustainable local development. This paper also analyzes the main responsibility, impetus, and interrelation of the three cycles and gives some suggestions on how to further promote implementation of the three-level water cycle.     

Nonionic surfactant enhanced biodegradation of m-xylene by mixed bacteria and its application in biotrickling filter

In this study, m-xylene biodegradation was examined in bacteria-water mixed solution and biotrickling filter (BTF) systems amended with the nonionic surfactant Tween 80. The mixed bacteria were obtained from the activated sludge of a coking plant through a multisubstrate acclimatization process. High-throughput sequencing analysis revealed that Rhodanobacter sp. was the dominant species among the mixed bacteria. In the bacteria-water mixed solution, the bacterial density increased with increasing Tween 80 concentration. Hence, Tween 80 could be utilized as substrate by the mixed bacteria. Tween 80, with concentrations of 50–100 mg L^?1, could enhance the bioavailability of m-xylene and consequently improve the degradation efficiency of m-xylene. However, further increasing the initial concentration of Tween 80 would decrease the degradation efficiency of m-xylene. At concentrations exceeding 100 mg L^?1, Tween 80 was preferentially degraded by the mixed bacteria over m-xylene. In BTF systems, when the m-xylene inlet concentration was 1200 mg m^?3 and the empty bed residence time was 20 sec, the removal efficiency and elimination capacity of BTF1 with Tween 80 addition were at most 20% and 24% higher than those of BTF2 without Tween 80 addition. Overall, the integrated application of the mixed bacteria and surfactant was demonstrated to be a highly effective strategy for m-xylene waste gas treatment.

Implications: The integrated application of mixed bacteria and surfactant was demonstrated to be a promising approach for the highly efficient removal of m-xylene. Surfactant can activate mixed bacteria to degrade m-xylene by increasing its bioavailability. Besides, surfactant can be utilized as carbon source by the mixed bacteria so that the growth of mixed bacteria can be promoted. It is expected that the integrated application of both technologies will become more common in future chemical industry.     

Nano-MnO<Subscript>2</Subscript>-mediated transformation of triclosan with humic molecules present: kinetics,products, and pathways

It has been shown that manganese dioxide (MnO₂) can mediate transformation of phenolic contaminants to form phenoxyl radical intermediates, and subsequently, these intermediates intercouple to form oligomers via covalent binding. However, the reaction kinetics and transformation mechanisms of phenolic contaminants with humic molecules present in nano-MnO₂-mediated systems were still unclear. In this study, it was proven that nano-MnO₂ were effective in transforming triclosan under acidic conditions (pH 3.5–5.0) during manganese reduction, and the apparent pseudo first-order kinetics rate constants (k?=?0.0599–1.5314 h^?1) increased as the pH decreased. In particular, the transformation of triclosan by nano-MnO₂ was enhanced in the presence of low-concentration humic acid (1–10 mg L^?1). The variation in the absorption of humic molecules at 275 nm supported possible covalent binding between humic molecules and triclosan in the nano-MnO₂-mediated systems. A total of four main intermediate products were identified by high-resolution mass spectrometry (HRMS), regardless of humic molecules present in the systems or not. These products correspond to a suite of radical intercoupling reactions (dimers and trimers), ether cleavage (2,4-dichlorophenol), and oxidation to quinone-like products, triggered by electron transfer from triclosan molecules to nano-MnO₂. A possible reaction pathway in humic acid solutions, including homo-coupling, decomposition, oxidation, and cross-coupling, was proposed. Our findings provide valuable information regarding the environmental fate and transformation mechanism of triclosan by nano-MnO₂ in complex water matrices.     

PVDF/ZrO2杂化膜的制备及其吸附刚果红的性能

采用浸没沉淀法制备了ZrO2共混的聚偏氟乙烯杂化膜,通过扫描电子显微镜（SEM）和热重（TG）对其结构进行了表征,并将其应用于对染料刚果红的吸附。考察了pH、温度、吸附时间和ZrO2用量对刚果红吸附的影响。结果表明：在弱酸性条件下有利于杂化膜对刚果红的吸附;随着ZrO2用量的增加,吸附量逐渐增加;在25℃条件下,吸附平衡时间为25 min,吸附动力学过程符合准二级动力学方程;Langmuir吸附模型能较好的描述等温吸附过程,最大吸附量达到0.271 7 mg·cm-2。     

低接种污泥量强化循环厌氧反应器(SCAR)处理生活污水

采用强化循环高效厌氧反应器(SCAR)处理生活污水研究反应器的启动过程和运行特性。在低接种污泥量、回流比R=0.5、HRT为16 h条件下经过65 d完成反应器启动,系统出水COD稳定在约80 mg·L^-1,VFA浓度约240 mg·L^-1,颗粒污泥性状良好,微生物活性增强。SCAR反应器对污染物的去除受水力停留时间和反应器外回流比影响,微生物生化反应时间和在反应器中的空间分布状态共同决定着反应器的运行效果。SCAR反应器脱氮作用明显,实验条件下反应器对总氮的去除主要是通过反硝化作用实现。     

基于化石碳的污泥干化焚烧处置碳排放分析

通常认为,污泥焚烧产生的CO₂是生物成因,不计入碳排放核算清单。但石油加工化学品的广泛使用会导致污泥化石碳质量分数增加。为符合实际情况,采用放射性碳测年法测定污泥化石碳质量分数。基于浙江省某2 500 t·d⁻¹污泥能源化利用热电联产项目运营数据,以1 t干基污泥 (DS) 为核算对象,构建碳排放及碳补偿核算方法,得出污泥干化焚烧-灰渣综合利用路径的碳排放因子,并与深度脱水-应急填埋路径的理论碳排放水平比较。结果表明,污泥有机碳中化石碳质量分数为64.94%,并非100%的生源碳。因此,污泥焚烧时计入碳排放核算清单的直接碳排放会增大,同时数据准确性和可靠度也有所增加。干化焚烧-灰渣综合利用路径中,1 t干基污泥的碳排放为0.32 tCO_2eq,约为深度脱水-应急填埋路径的1/6,更具减排潜力。本研究结果可为污泥低碳化处理处置提供参考。     

夏季白洋淀颗粒的有机质碳氮同位素特征及其来源解析

为阐明白洋淀颗粒有机质碳氮同位素空间分布差异及其来源,于2022年9月测定了白洋淀夏季悬浮颗粒物样品中颗粒有机碳 (POC) 、颗粒有机氮 (PON) 、δ¹³C和δ¹⁵N,并运用MixSIAR模型对颗粒有机质来源进行分析。结果表明,白洋淀内POC和PON质量分数分别为3.55%~21.91%和0.44%~2.93%,全淀区POC和PON整体水平处于8.60%±5.52%和1.14%±0.72%,受入淀河流的影响,POC、PON整体空间分布存在较大差异;δ¹³C和δ¹⁵N的范围分别为−25.27‰~−32.95‰和3.86‰~7.32‰,呈由淀南向淀北逐渐偏正的趋势,表明由南向北外源贡献升高,自生源贡献降低。贝叶斯混合模型计算结果表明,悬浮颗粒有机质主要来源于浮游植物 (28.60%~37.40%) 、陆源植物 (22.40%~34.30%) 和水生植物 (30.20%~31.30%) ,内源自生贡献率高达59.90%。基于上述研究,提出在适当的时期通过收割淀内芦苇等挺水植物及适当的对沉水植物及藻类残体进行打捞的工程措施,可有效降低自生源对于有机质的贡献,进而切断有机质对于水环境中有机碳氮的贡献,确保水质的达标和稳固提升。本研究结果可为白洋淀的水质保护及修复提供理论参考。     

长江、嘉陵江(重庆段)源水有机提取物的致突变活性及其季节变化

为了确定并比较重庆主城区段长江、嘉陵江源水有机提取物的致突变性及其季节变化规律，分别于春、夏、冬季采用GDX－120大孔树脂，对位于城区上游、城区中段、城区下游以长江、嘉陵江源水的5个水厂的进厂水进行了有机物的浓缩提取。提取物的致突变活性采用经典的Ames试验平板掺入法评估，测试菌株为TA98及TA100，同时做加与不加S9的比较。结果显示，嘉陵江及长江源水的有机提取物均有不同程度的致突变活性。嘉陵江源水明显大于长江源水，城区中段源水明显大于上游段及下游段源水。多数断面显示平水期致突变活较为显著并且移码型致突变性大于碱基置换型致密变性。研究结果提示，城市污染源已导致长江、嘉陵江源水具备致突变活性，控制两江沿岸的各种水污染源已成为当务之急。     

发达国家污染土地置换开发管理实践及其对我国的启示

污染土地置换开发是一个复杂的过程,涉及技术、法律、经济和社会等诸多问题.选择管理技术相对比较成熟和先进的美国、欧盟国家、加拿大以及日本作为案例,深刻剖析国际上污染土地置换开发管理的经验与教训,提出有效的城市土地利用规划、公平合理的经济责任界定、合适的资金筹措机制、灵活选择土壤污染修复目标、污染土地风险评估等级划分、多利益方的共同参与等6点启示,以期对我国日益受到重视的污染土地置换开发管理工作提供借鉴.     

柔性电路板清洁生产措施浅述

通过对柔性线路板生产工艺、过程控制、能耗控制、污染防治技术等方面措施的论述，为柔性线路板项目实现，清洁生产提供帮助。